KR20190002675A - Training method and system for directional transmission in wireless communication - Google Patents

Abstract

There is provided a wireless radio communication apparatus and method in which training of directional transmission, also known as beamforming, is performed in transmissions between a plurality of wireless radio communication devices participating in a local network. The sector level sweep (SLS) process uses transmitter sector sweep (TXSS) training, which includes sending sector sweep (SSW), followed by generating sector sweep (SSW) feedback to other nodes in the local network , The optimal transmission sector information is exchanged between the nodes. Embodiments include a power save mode, a delayed SSW feedback mode, and an embedded polling and feedback mode.

Description

Training method and system for directional transmission in wireless communication

Cross reference of related applications

Not applicable

A description of federal-sponsored research or development

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Integration by reference in computer program appendix

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Notice of copyright protection

Some of the contents of this patent document are subject to copyright protection in accordance with the copyright laws of the United States and other countries. The owner of the copyrighted rights has no objection to the copying of the patent document or by anyone in the patent disclosure, as shown in the files or records disclosed in the United States Patent and Trademark Office, but otherwise owns all copyright rights. The copyright owner hereby authorizes 37 C.F.R. Do not waive any of the rights to keep this patent document confidential, including without limitation rights under § 1.14.

The teachings of this disclosure relate generally to wireless network communications, and particularly to transmit sector sweep (TXSS) training for group SLS.

Highly directional communications, especially communications using beamforming techniques, are often needed to overcome poor link budgets in wireless communications such as mmWave frequencies.

Creation of robust networks for wireless communication networks requires periodic beamforming training to account for link closure, movement of nodes or surroundings, and similar obstructions.

Figure 1A shows an exemplary network with four nodes and an access point (AP) as a first station (STA 1) is shown with additional stations STA 2, STA 3, and STA 4.

1B shows a superframe in which a header section and a data transmission period are marked and shows the sections of this superframe required for beamforming (BF) training and thus includes a BF training overhead.

When multiple stations (STAs) in the network communicate with each other or with APs in peer-to-peer (P2P) mode, BF training becomes highly inefficient. The BF training of these STAs can be performed in a number of steps and can span a number of super-frames, consuming a significant portion of the air time of communications. Thus, beamforming improves coverage and link quality, but results in significant overhead during training.

Therefore, there is a need for improved beamforming training that reduces the overhead of the required communications. The present disclosure satisfies the need while providing the benefits of additional wireless networking.

The apparatus and method are described with enhanced beamforming training for use in wireless communication systems. The disclosed apparatus provides coordination of transmit sector sweep (TXSS) training signaled by a master station (STA) such as an access point (AP) or other station in a given local network. The mutual TXSS is performed between a group of STAs where every STA listens (receives) sector sweep (SSW) frames of other STAs and uses it for mutual TXSS training. In addition, STAs can learn TXSS training results, such as the optimal transmit sector, of all links in the network of STAs participating in the TXSS by receiving SSW feedback from all STAs. In at least one embodiment, the system is configured to use sleep / awake signaling for the TXSS power save mode. In other embodiments, variations are described using delayed SSW feedback, or embedded polling and feedback. Thus, the present disclosure can provide an improved wireless experience, for example, when using millimeter-wave (mmWave) wireless local area networks (WLANs).

A number of terms are used in this disclosure, and their meanings are generally used as described below.

AID (Association Identifier): The association identifier is used whenever the station associates with an AP (master station or central radio coordinator or other initiator), and the station receives the AID. This AID is used to track the members of the associated station and the base service set (BSS).

AP (Access Point): An access point is an entity that includes one station (STA) and provides access to distribution services via wireless media (WM) for associated STAs.

AoA (Angle of Departure): An angle of arrival (departure angle) that indicates the direction of propagation of a radio-frequency wave that is incident (transmitted) on an antenna array (from an antenna array).

Association-Beamforming Training period (A-BFT): The associative-beamforming training period is a period that is guided in association of new stations participating in the network and in beacons used for BF training.

Beamforming (BF) is a process of pageing antennas in an array to achieve directional transmission (beamforming) that does not use an omnidirectional antenna pattern or a quasi-omnidirectional antenna pattern. This is used at the transmitter to improve the power or signal-to-noise ratio (SNR) of the signal received at the intended receiver.

Beam combining is a method for combining power contained in various beams at a receiver for each independent data stream.

Basic Service Set (BSS): The basic service set is a set of stations (STAs) successfully synchronized with APs in the network.

BI (Beacon Interval): The beacon period is a cycle superframe period indicating the time between beacon transmission times.

BRP (BF Refinement Protocol): The BF Refinement protocol enables receiver training and iteratively trains transmitter and receiver sides to achieve the best (possible) possible directional communications.

Contention-Based Access Period (CBAP): The contention-based access period is the time period within the data transmission interval (DTI) of the directional multi-gigabit (DMG) BSS in which contention-based enhanced distributed channel access (EDCA) is used.

DTI (Data Transfer Interval): The data transmission interval is a period in which actual data is transmitted following the permission of complete BF training. Which may include one or more service periods (SP) and a contention-based access period (CBAP).

ISS (Initiator Sector Sweep): Initiator sector sweep.

MAC Address (Medium Access Control address): Medium access control (MAC) address.

Modulation and Coding Scheme (MCS): The modulation and coding scheme is an index that can be converted into a PHY layer data rate.

Omni directional: omnidirectional is the non-directional antenna mode of transmission.

Quasi-omni directional: Quasi-omni directional is a directional multi-gigabit (DMG) antenna operating mode that can achieve the widest beamwidth.

Receive Sector Sweep: Reception of sector sweep (SSW) frames from different directional sectors, where sweeps are performed between successive receivings.

(I) an initiator sector sweep (ISS) for training the initiator, (ii) a sector-level sweep (SLS) phase, Responder sector sweep (RSS) to train respondent link, (iii) SSW feedback, and (iv) SSW ACK.

RSSI (Receive Signal Strength Indicator): The received signal strength indicator (in dBm) is a measure of signal strength.

Service Period (SP): The service period is scheduled by an access point (AP). Scheduled SPs start at fixed intervals of time.

STA (Station): A station is a logical entity that is a single addressable instance of a medium access control (MAC) and physical layer (PHY) interface to a wireless medium (WM).

Sweep: A sequence of transmissions separated by a Short Beamforming Interframe Space (SBIFS) period, in which the antenna configuration at the transmitter or receiver changes between transmissions.

Transmit sector sweep (TXSS): Transmission of multiple sector sweeps (SSW) or directional multi-gigabit (DMG) beacon frames across different sectors, where sweeps are performed between consecutive transmissions.

Additional aspects of the techniques described herein will be apparent in the remainder of the specification and the detailed description is intended to fully disclose preferred embodiments of the invention without limiting it thereto.

The techniques described herein will be more fully understood by reference to the following drawings for purposes of illustration only:
1A is a radio node diagram illustrating communication between an access point (AP) and three different stations (STAs).
1B is a data field format of the beamforming (BF) training overhead in the header and data transmission periods of the superframe.
Figure 2 is a beam pattern diagram illustrating the best beam pattern sectors between two stations.
3 is an air time diagram of sector level sweeping (SLS) between the transmitter and the responder.
4 is an air time diagram of a beacon header interval (BHI) in which an initiator and a number of responder TXSSs are performed within a superframe header.
5 is a message sequence of SLS BF training between an AP and multiple STAs in the 802.11ad standard.
Figure 6 is an air time diagram illustrating possible contention between STAs responding during the A-BFT period.
7 is a data field format of the SSW control frame.
Figure 8 is a data field format for the SSW field in the control frame.
9A and 9B are data field formats for the SSW feedback field, the format shown in FIG. 9A is used when transmitted as part of the ISS, and the format shown in FIG. 9B is not used as part of the ISS , Each compliant with the 802.11ad standard.
10 is a data field format for a sector sweep feedback frame (SSW-feedback frame) in the 802.11ad standard.
Figure 11 is a radio node diagram used as an example when discussing embodiments of the present disclosure.
12 is a data field format for an SLS polling (SLS-P) information element (IE), used in accordance with an embodiment of the present disclosure.
13 is a message sequence for a broadcast SLS protocol with immediate SSW feedback according to an embodiment of the present disclosure.
14 is a flow chart for a broadcast SLS protocol with immediate SSW feedback according to an embodiment of the present disclosure.
Figure 15 is a broadcast SLS polling frame format, in accordance with an embodiment of the present disclosure.
16A and 16B are data field formats for a broadcast SLS, which illustrate an SSW frame format and an SLS SSW feedback frame format, respectively, in accordance with an embodiment of the present disclosure.
Figure 17 is a data field format for one of the SSW feedback fields shown in Figure 16B, in accordance with an embodiment of the present disclosure.
18 is a message sequence for a broadcast SLS protocol with a power save mode, in accordance with an embodiment of the present disclosure;
19 is a message sequence for a broadcast SLS protocol with delayed feedback, in accordance with an embodiment of the present disclosure;
20 is a flow diagram of a broadcast SLS protocol with delayed feedback as shown in FIG. 19, in accordance with an embodiment of the present disclosure.
21 is a message sequence for an SLS protocol with embedded polling and feedback, in accordance with an embodiment of the present disclosure;
22 is a flow diagram of an SLS protocol with embedded polling and feedback, as shown in FIG. 21 and shown at the initiator STA's perspective, in accordance with an embodiment of the present disclosure;
23 is a flow diagram of an SLS protocol with embedded polling and feedback, as shown in Fig. 21 and shown at the non-initiator STA's perspective, in accordance with an embodiment of the present disclosure.
24A and 24B are data field formats for the contents of the SSW frame formats from each of the initiator and non-initiator utilized in accordance with an embodiment of the present disclosure.

1. Cutting-edge mmWave technology.

mmWave WLAN An example of a state-of-the-art system is the 802.11ad standard. In this standard, BF training is a bi-directional sequence of BF training frame transmissions that utilizes a sector sweep and provides the necessary signaling that allows each STA to determine appropriate antenna system settings for both transmit and receive.

In 802.11ad, the BF training process can be performed step by step. (a) The sector level sweep step performs directional transmission combined with low gain (quasi-omnidirectional) reception for link acquisition. (b) a refinement step is performed to add the receive gain and final control for the combined transmit and receive. (c) Tracking is performed during data transmission to adjust for channel changes. It should be appreciated that this specification focuses primarily on improvements to the essential steps of the sector-level sweep (SLS) of the 802.11ad standard.

1.1 The sector-level sweep (SLS) concept of BF training.

The following sections describe the most advanced BF training according to the 802.11ad standard. During SLS, a pair of STAs exchanges a series of sector sweep (SSW) frames (or beacons in the case of transmit sector training in a PCP / AP) through different antenna sectors to find the best signal quality. The first transmitting station is called the initiator, and the second is called the responder.

During transmit sector sweep (TXSS), the pairing node (responder) receives in a quasi-omnidirectional pattern, while SSW frames are sent to different sectors. The responder determines the antenna array sector from the initiator at which the best SNR is provided.

Figure 2 shows beam pattern diagrams from a transmitter (STA 1) and a receiver (STA 2), where the best sectors for each other are shown in the figure.

Each packet of the transmit sector sweep includes a countdown indication (CDOWN), a sector ID, and an antenna ID. The best sector ID and antenna ID information is fed back with sector sweep feedback and sector sweep ACK packets.

3 shows a sector level sweep (SLS) between STA 1 and STA 2 during which the STA 1 performs a transmit sector sweep (TXSS) during an initiator sector sweep (ISS). The sector sweep feedback (SSW feedback) is sent to the STA 1, and then the sector sweep acknowledgment (ACK) is sent to the STA 2 during the responder sector sweep (SSW) Lt; / RTI >

As an example of applying SLS to multiple STAs, the SLS occurring during the beacon header interval (BHI) of the 802.11ad superframe is considered below. In this SLS, the AP performs the initiator TXSS in the beacon transmission interval (BTI). The STAs respond by receiving (receiving) this information and performing a responder TXSS for the A-BFT period.

4 illustrates a beacon header interval (BTS), which illustrates sector-level sweeping with an initiator TXSS during a beacon transmission interval (BTI), with multiple responders performing a TXSS during an Association-Beamforming Training (A- BHI).

However, STAs respond to the TXSS in an uncoordinated fashion. In particular, STAs perform a random back-off and a collision is assumed if no SSW feedback is received from the AP. The SSW ACK may be transmitted during the information transmission interval (ATI).

5 shows a message sequence illustrating an SLS BF training procedure between an AP and a plurality of STAs in 802.11ad. The top row of the drawing shows activity by AP / PCP (PCP stands for PBSS control point), and the rows below show activity for STA 1 and STA 2. During the BTI interval, the initiator TXSS is performed by the AP / PCP using SSW frames (DMG beacons) received by STA1 (state S_12) and STA2 (state S_13). During the A-BFT interval, STA 1 is the first responder to perform the TXSS and shows sending SSW frames back to the AP / PCP. The responder TXSS is received (state S_21) and the AP / PCP sends SSW feedback to STA1. After a few cycles in the A-BFT, STA 2 performs the response TXSS and the response TXSS is received by the AP / PCP responding to STA 2 with SSW feedback (state S_31).

Figure 6 is an illustration of the contention that may occur between multiple responders during the A-BFT period. Current state-of-the-art 802.11ad implementations that train groups of multiple STAs lead contention during A-BFT. In the figure, an example is shown in which each SSW slot has a length of 8 and has an A-BFT that accommodates eight SSW frames. A possible contention occurs between the three STAs (STA A, STA B, and STA C) that compete for access. In this scenario, all STAs select a random value between [0, 7]. In the example shown, STA A selects a value of 2 and STA B and C select a value of 5, which may cause collisions of communications with the AP / PCP.

Figure 7 shows the fields for a sector sweep frame (SSW frame) used in the 802.11ad standard, the fields of which are outlined below. The duration field is set to the time until the end of SSW frame transmission. The RA field contains the MAC address of the STA, which is the intended receiver of the sector sweep. The TA field contains the MAC address of the transmitter STA of the sector sweep frame.

Figure 8 shows data fields for the SSW field. The principle information transmitted in the SSW field is as follows. The direction field is set to zero to indicate that the frame is to be transmitted by the beamforming initiator and is set to one to indicate that the frame is to be transmitted by the beamforming responder. The CDOWN field is a down-counter that indicates the number of DMG beacon frame transmissions remaining until the end of the TXSS. The sector ID field is set to indicate the number of sectors to which the frame including this SSW field is transmitted. The DMG Antenna ID field indicates which DMG antenna the transmitter is currently using for this transmission. The RXSS length field is only validated when transmitted in the CBAP and is otherwise reserved. This RXSS length field specifies the length of the received sector sweep required by the sending STA and is defined as the units of SSW frames. The SSW feedback field is defined below.

Figures 9A and 9B show the SSW feedback field. The format shown in FIG. 9A is used when it is transmitted as part of the ISS, and the format shown in FIG. 9B is used when it is not transmitted as part of the ISS. The total sectors in the ISS field indicate the total number of sectors the initiator uses in the ISS. The number of sub-fields of the RX DMG antennas indicates the number of receive DMG antennas that the initiator uses during the subsequent received sector sweep (RSS). The sector select field contains the value of the sector ID subfield of the SSW field in the frame received with the best quality in the immediately preceding sector sweep. The DMG antenna selection field indicates the value of the DMG antenna ID subfield of the SSW field in the frame received with the best quality in the immediately preceding sector sweep. The SNR report field is set to the SNR value from the frame received in the best quality during the immediately preceding sector sweep and displayed in the sector selection field. The Poll Required field is set to 1 by the non-PCP / non-AP STA to indicate that the PCP / AP is required to initiate communication with the non-PCP / non-AP. To indicate that the non-PCP / non-AP has no preference as to whether the PCP / AP initiates the communication, the poll request field is set to zero.

Figure 10 shows data fields for a sector sweep feedback frame (SSW-feedback frame) in the 802.11ad standard. The duration field is set to zero when the SSW-feedback frame is transmitted within the associated beamforming training (A-BFT). Otherwise, the duration field is set to microseconds, to the end of the current allocation. The RA field contains the MAC address of the STA, which is the intended destination of the SW-feedback frame. The TA field contains the MAC address of the STA transmitting the SSW-feedback frame. The BRP request field provides the information needed to initiate the BRP process. The Beamforming Link Retention field provides the value of the beam link retention time to the DMG STA. When the beam link retention time elapses, the link operates in the quasi-omnidirectional Rx mode.

The distinctions of the disclosed apparatus and method, together with the above background information on conventional state of the art 802.11ad mmWave operations, should be more readily understood.

2. Introduction to TXSS training, which is launched.

The following sections disclose various embodiments of the SLS protocol and variations thereof.

2.1 General description of the SLS protocol

11 shows a radio network showing AP (STA 1) with two stations (STA 2, STA 3), and mutual TXSS training is performed between STAs, the following exemplary embodiments being described . The proposed group SLS protocol is applicable to wireless networks and is particularly suitable for mmWave wireless networks. The teachings of the present disclosure, including the following, provide a number of advantages. (a) coordination of SSW frames and feedback controlled by the initiator STA; This polling of training signaling prevents contention between STAs to transmit SSW frames. (b) All STAs transmit SSW frames once, and then, at the end of the SLS phase, STAs exchange best sector information. (c) In one implementation of the disclosed SLS protocol, all STAs may also be notified of the best transmit sector for each link in the network of contributing nodes.

2.2 SLS Polling (SLS-P) Information Element (IE).

Figure 12 shows the data field format for the SLS polling (SLS-P) information element (IE). This information is commonly used in all types of implementations of this disclosure. The coordinator sends the polling information to adjust the SSW frames. An AP in the network may act as a coordinator, and in other cases a non-AP STA may be used. The SLS-P IE has the following fields. The IE ID is the number of bits that are interpreted by the STAs as the SLS polling announcement IE. The length field is the length in bytes of the IE. The STA ID field is an ordered list of STA IDs participating in group SLS training. The Timing Offset field is an ordered list of time offsets for SSW transmission or SSW feedback. The use field is a bit indicating SSW or SSW feedback.

2.3 Broadcast SLS Protocol Overview.

Consider one embodiment of the proposed group SLS in which the STAs contributing to the group SLS protocol are within close range. In this case, transmission and reception to the quasi-omnidirectional mode (no Tx or Rx directionality) with the use of low rate control PHYs can still provide reliable communications. For example, transmission at the maximum spacing between MCS0 of 802.11ad, Tx power of about 17dBm (for all STAs), STA of about 15m, the following parameters are higher than the MCS0 sensitivity of -78dBm in bandwidth of 2GHz Resulting in an RSSI of approximately -74 dBm.

2.3.1 Broadcast SLS protocol with immediate SSW feedback.

In this exemplary scenario, the group SLS protocol operates as follows. (B) the transmission time of SSW frames for each contributing STA, and (c) the SSW feedback frame (s) for each contributing STA. The initiator STA (e.g., AP / PCP) (In a quasi-omnidirectional mode) that includes the transmission time of the polling signal. Next, the initiator STA transmits SSW frames. All other STAs receive and follow the timing of the polling signal to transmit SSW feedback following their SSW frames. All STAs receiving SSW frames memorize (store) the best sector for that link and transmit this information in the feedback SSW frames. In this close range embodiment, the feedback SSW frames are preferably sent in a quasi-omnidirectional mode. Thus, this information can be received by all other STAs in the BSS. Therefore, this embodiment will be recognized as separating the feedback information from the SSW frames.

13 shows an exemplary message sequence using a broadcast SLS protocol with immediate SSW feedback. In this figure, communications between the initiator (STA 1) shown on the top line of the figure and STA 2 and STA 3 shown on the bottom lines of the figure are shown. An initiator TXSS is shown following polling using omnidirectional transmission for STA1. The polling frame contains information when each scheduled transmission from STA 2 and STA 3 is to be transmitted, so that they do not collide with each other. This activity is registered by STA2 and STA3 in the respective states S_12 and S_13, respectively, which memorize (store) the best directional sectors for a particular link. The STA 2 then uses the all-directional transmission to provide SSW feedback, followed by the first responder TXSS. STA 1 and STA 3 register this activity by STA 2. Immediately after the end of the first responder TXSS, STA 1 provides SSW feedback to STA 2. STA 3 then uses the all-directional transmission and provides SSW feedback to STA 2 in accordance with the timing provided by the polling signal, and then generates a second responder TXSS. This activity is shown to be registered by STA 1 (state S_31), and STA 2 (state S_32), and states again store the best sectors for each communication.

FIG. 14 shows an exemplary flow diagram 10 for a broadcast SLS protocol with immediate SSW feedback according to an embodiment of the present disclosure. The value n representing the station number is started in block 12, for example 1, and the total number of stations in the network (BSS) at a given time is given by the value N. [ The initiator (e.g., STA 1) prepares a scheduling table for the SLS protocol (14). STA 1 transmits a group SLS polling frame for forwarding the contents of the scheduling table to STAs participating in the group SLS protocol (16). STA 1 transmits SSW frames (18). In order to determine if all stations have been processed, a determination is made whether n is greater than N (20). If yes, the process moves to completion (end) 30 for all stations. If n is still less than N, processing proceeds to block 22, where the initiator processes the feedback from STA n and stores information about the best sector information from STA n to STA n-1. Next, the initiator STA listens (monitors and receives) SSW frames from STA n (24) and determines the best transmission sector of communication from STA n to itself. Initiator STA sends feedback for the best sector of STA n and stores information about the best sector from STA n (26). The value n increases (28) for the next pass, with execution returning to block 20, until n is greater than N. [ It will be appreciated by those of ordinary skill in the art that a flow diagram may be modified in a number of ways without departing from the present disclosure, which performs the processing described for each station.

15 is an SLS beamforming polling frame having the following fields. The frame control field includes information on the type of frame, power management information, frame to be retried, and the like. The duration field indicates the duration of the frame in microseconds. The RA field is the MAC address identifying the intended recipient STA (s), in which case the RA is set to the broadcast group address. The TA field is the MAC sender address that identifies the STA that sent this frame. The SLS-P IE field is an SLS polling information element, as described in the previous section. The FCS field is a frame check sequence for confirming reception of frame contents.

16A shows an example of a broadcast SLS SSW frame format. The SLS SSW feedback frame format includes the following fields. The frame control field includes information on the type of frame, power management information, frame to be retried, and the like. The duration field indicates the duration of the frame in microseconds. The RA field is the MAC address that identifies the intended recipient STA (s) and is set for broadcast or multicast. The TA field is a MAC address that identifies the STA transmitting the frame. The SSW field is described in FIG. The FCS field is a frame check sequence for confirming reception of frame contents. In this embodiment, the SSW feedback is separated from the SSW frames.

16B shows an exemplary format for a broadcast SLS SSW feedback frame. The frame control field includes information on the type of frame, power management information, frame to be retried, and the like. The duration field indicates the duration of the frame in microseconds. The RA field is a MAC address that identifies the intended recipient STA (s) to be set for broadcast or multicast. The TA field is a MAC address that identifies the STA transmitting the frame. The SSW feedback field contains a number of fields, one field for each STA in the local network, for example when N is the number of STAs ... There are N fields. The FCS field is a frame check sequence for confirming reception of frame contents.

FIG. 17 shows exemplary fields within one of the SSW feedback fields shown in FIG. 16B. The SSW feedback field includes the following fields. The STA ID subfield indicates to which neighboring STA the SSW feedback is intended. The sector select subfield is the value of the sector ID subfield of the SSW field in the frame received with the best quality in the previous sector sweep immediately prior to STA1. The antenna selection subfield is the value of the DMG antenna ID subfield of the SSW field in the frame received with the best quality in the previous sector sweep immediately prior to STA1. The SNR reporting subfield is the value of the SNR from the frame received in the best quality during the immediately preceding sector sweep and displayed in the sector selection field.

18 is a time diagram for a broadcast SLS protocol with a power save mode. In this embodiment of the SLS protocol, a power saving mode is provided in which each STA schedules the sleep / awake periods for the receiver based on the polling signal contents. Each STA performs a mutual TXSS with all the other STAs in the network, but ignores the best sector information of the links to which the STA does not belong.

Referring to Fig. 18, this timing is almost the same as the timing of Fig. 13, and it can be seen that the power saving mode is added. The bottom row of the figure shows the sleep / awake signal for STA 3 so that the receiver of STA 3 is in the awake state when this signal is high and the receiver of STA 3 is in the sleep state when the signal is low. This signal is generated by each STA after processing the polling frame contents transmitted by the initiator STA at the start of the group SLS protocol. For example, the STA 3 receiver will remain awake until it detects a polling signal. From the polling signal, it will identify the start time of transmission of the SSW frames by different STAs comprising the initiator STA. The STA3 receiver is in an awake state during these SSW frame transmissions and when it expects to detect corresponding SSW feedback from other STAs immediately after transmission of its own SSW frames. The STA 3 receiver switches to sleep (sleep) mode during transmission of SSW feedback frames from other STAs that do not respond to STA 3 SSW frames.

Figure 19 shows a broadcast SLS protocol using delayed feedback. The first part of this messaging timeline is almost identical to that of FIG. 13, but it can be seen that the SSW feedback signals are coupled and delayed up to the period of the SSW feedback signals. This embodiment uses two periods, where the two periods are a first period for SSW frames and a second period for feedback signals as shown in the figure. In this case, the feedback signal may collect the best sector contents for a plurality of STAs. As shown in the figure, the stations do not send their SSW feedback signals until all the stations have performed their TXSS, the initiator sends its SSW feedback first, and the other stations then send their respective SSW feedback . In this embodiment, the feedback overhead is reduced and the scheduling of SSW and SSW feedback transmissions is simplified.

FIG. 20 shows an exemplary embodiment 50 of this delayed SSW feedback, as shown in FIG. 19, and controlled by an initiator STA. The value n representing the station number is initiated, for example, at 1 in block 52, and the total number of stations participating in the group SLS belonging to the network (BSS) is given by the value N. [ The initiator (e.g., STA1) prepares a scheduling table for the SLS protocol (54). STA 1 transmits (56) a group SLS polling frame that conveys the contents of the scheduling table to the remaining STAs, and then transmits (58) SSW frames. A determination is made whether n is greater than N, which is a determination 60 that all stations have performed TXSS processing. If not (if n is still less than N), then the process is initiated by the initiator listening (monitoring and receiving) and processing the feedback from STA n and selecting the best (e.g., lowest noise) And proceeds to block 62 for storing information on the transmission sector. Next, the initiator STA listens (monitors and receives) SSW frames from STA n (64) and determines the best communication transmission sector from STA n to itself. The value n is then incremented for the next pass (64) and execution returns to block (60). If at block 60 n is found to be greater than N, execution moves to block 66 where the initiator STA sends feedback to the best sectors for all the other (N-1) stations, And stores information on the best sector information from the STA n. The initiator STA then processes (68) the feedback from the rest of the (N-1) stations and the routine ends (70). It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit of the disclosure.

2.4 SLS protocol with built-in polling and feedback.

In this embodiment, since STAs are not considered within close range, transmission is done with Tx directionality to overcome link budget constraints. Three basic steps of this process are described below. (i) The polling signal is included in initiator SSW frames. (ii) SSW frames of responder STAs convey feedback to the initiator, or to the best sector for the link with another STA to which the SSW frames have just been transmitted. (iii) the feedback signals (SSW feedback) are transmitted to the best array sector according to the information carried in the SSW frames of the STA at the other end of the link. When the SLS protocol terminates, a mutual TXSS exchange between each STA and every other STA in the network is achieved.

Figure 21 shows an SLS protocol using transmit beamforming for polling and SSW feedback signals. In this messaging timeline, it can be seen that there is no polling transmission block as shown in FIG. Instead, an initiator polling signal is included in initiator SSW frames (SSW + polling information). SSW feedback is included in the SSW frames (e.g., SSW + S_12 feedback and SSW + S_13 & S_23) and is transmitted separately by the STA in a beamforming manner if the STA has already transmitted SSW frames in the past. This distinction of transmission of the SSW feedback embedded in the top of the SSW frames or in a separate transmission block is further illustrated in the non-initiator STA flow chart of FIG.

22 illustrates an exemplary embodiment 90 of such embedded polling and feedback as shown in FIG. 21, at the time of initiator STA. The value n indicating the station number is started at block 92, for example, The total number of stations in the network participating in the SLS training protocol at a given time is given by the N value. The initiator STA (e.g., STA1) prepares a scheduling table for the SLS protocol (94). STA 1 transmits the SSW frame together with the SLS polling IE embedded in the SSW frame (96). A determination is made whether n is greater than N, i. e., all stations have been processed (98). If yes, i.e. if n is greater than N, then processing is complete for all stations and end 108 is reached. However, if n is still less than N, processing proceeds to block 100 where the initiator STA listens (monitors and receives) SSW frames from n stations and processes the embedded SSW feedback from that station. At block 102, the initiator STA determines the best Tx sector of STA n for itself. At block 104, the initiator STA sends a directional transmission to the STA n based on the processed SSW feedback received from the STA n, an SSW feedback frame containing information about the best Tx sector for that station. The value n is incremented 106 for the next pass, execution returns to block 98, and the loop proceeds until n is greater than N. [ It will be appreciated by those of ordinary skill in the art that changes may be made in the above flow diagrams in a number of ways without departing from the present disclosure.

FIG. 23 illustrates an exemplary embodiment 130 of such embedded polling and feedback at the perspective of a non-initiator station providing delayed feedback. The STA listens to the SSW frame from the initiator STA and processes its embedded Polling IE. Next, the non-initiator station continuously listens for (134) SSW frames from other STAs and determines and stores the best Tx sector of all other STAs for itself. At block 136, the non-initiator station determines whether its SSW transmission time counter has expired. This counter is activated with a value determined from the polling IE contents after processing the polling IE from the initiator STA. This counter expires after SSW frame transmissions have been performed by this non-initiator STA. If the time counter has not expired, execution returns to block 134 where the non-initiator STA listens to the SSW frames of the other STAs. Otherwise, i. E. When the station time counter expires, the non-initiator STA puts the SSW feedback information in the Tx queue (138). The station transmits the SSW frames and embeds the SSW feedback field (140). The non-initiator STA then processes (142) feedback from other STAs as addressed in the SSW feedback field, continues to listen for SSW frames from the STA that have not yet sent the SSW frame ( 144) and determines and stores the best Tx sector of that STA for itself. This non-initiator STA then sends an SW feedback frame to that STA (146), thus terminating the routine (148).

24A illustrates exemplary fields in an initiator SLS SSW frame. The frame control field includes information on the frame type, power management information, frame to be retried, and the like. The duration field provides duration information for the frame in microseconds. The RA field is the MAC address identifying the intended recipient STA (s), and the RA is set to the broadcast group address. The TA field is a MAC address that identifies the STA transmitting the frame. The SSW field was previously defined. The SLS_P IE field is a previously defined SLS polling information element. The FCS field is a frame check sequence for confirming reception of frame contents.

Figure 24B shows exemplary fields in a non-initiator SLS SSW frame. The frame control field includes information on the type of frame, power management information, frame to be retried, and the like. The duration field provides the duration of the frame in microseconds. The RA field is the MAC address that identifies the intended recipient STA and is set for broadcast or multicast. The TA field is the MAC sender address that identifies the STA that sent this frame. The SSW field and the SSW feedback field have been previously defined. The FCS field is a frame check sequence for confirming reception of frame contents.

The enhancements described in this description may be readily implemented within various wireless radio networking nodes (e.g., APs and STAs). Each of these wireless radio nodes preferably includes at least one computer processor device (e.g., CPU, microprocessor, microcontroller, computer-usable ASIC, etc.), and programming (E.g., RAM, DRAM, NVRAM, FLASH, computer-readable media, etc.) that stores instructions to be executed by the processor to perform the steps of the various process methods .

As one of ordinary skill in the art would recognize the use of computer devices to perform the steps associated with networked radio communications, the computer and memory devices are not shown in the drawings for simplicity of illustration. The techniques presented are non-limiting with respect to memory and computer readable media, so long as they are non-transient and thus constitute transient electronic signals.

Embodiments of the present technique may be practiced with other methods and systems, including flowcharts of methods and systems according to embodiments of the present technique, and / or procedures, algorithms, steps, operations, formulas , ≪ / RTI > or other computing situations. In this regard, each block or step of the flowchart, as well as combinations of blocks (and / or steps), as well as any procedure, algorithm, step, operation, And software comprising one or more computer program instructions embodied in computer-readable program code. As will be appreciated, any such computer program instructions may be executed by one or more computer processors, or other programmable devices, including, but not limited to, a general purpose computer or special purpose computer, The instructions, when executed on a computer processor (s) or other programmable processing device, create a means for implementing the specified function (s).

Thus, blocks, procedures, algorithms, steps, operations, formulas, or computational schemes of the flowcharts described herein may be implemented with any combination of means for performing the specified function (s) Combinations of steps for performing the specified function (s), and computer program instructions, such as those embodied in computer-readable program code logic means for performing the specified function (s). Each block of flowchart illustrations, as well as any procedures, algorithms, steps, operations, formulas or computational views and combinations thereof described herein, (S), or special purpose hardware-based computer systems that perform combinations of special purpose hardware and computer-readable program code.

Moreover, such computer program instructions, such as those embodied in computer-readable program code, may be stored in computer-readable memory or in memory devices such that instructions stored in memory devices Readable memory or memory device capable of directing a computer processor or other programmable processing apparatus to function in a particular manner so as to produce an article of manufacture, (S), procedure (s), algorithm (s), step (s), operation (s), formula (s), or computational It will be appreciated that a computer processor or other programmable processing device (not shown) may be used to cause a series of operating steps to be performed in a computer processor or other programmable processing device to create a computer- The computer program instructions may also be executed.

The term " programming " or " program executable ", as used herein, refers to one or more instructions that may be executed by one or more computer processors to perform one or more functions described herein. . The instructions may be implemented in software, firmware, or a combination of software and firmware. The instructions may be stored locally on the device in the non-transient medium, remotely stored as stored on the server, or all or part of the instructions may be stored locally and remotely. Remotely stored commands may be automatically downloaded (pushed) to the device by user initiation, or based on one or more factors.

As used herein, the terms processor, computer processor, central processing unit (CPU), and computer are used to denote devices capable of executing instructions and communicating with input / output interfaces and / or peripheral devices It will be further understood that the terms processor, computer processor, CPU, and computer are intended to include single or multiple devices, single core and multi-core devices, and variations thereof.

From the description herein, it will be appreciated that the present disclosure encompasses a number of embodiments including, but not limited to, the following.

1. A wireless radio communication device for providing directional transmission between a plurality of wireless radio communication devices, comprising: (a) a transmitter configured to generate directional radio transmissions to other wireless radio communication devices in range; (b) a receiver configured to receive radio transmissions from other wireless radio communication devices; (c) a computer processor coupled to the transmitter and the receiver to control communications between itself and other wireless radio communication devices; (d) a non-transitory computer-readable memory that stores instructions executable by a computer processor; (e) when executed by a computer processor, (SLS) process in which beamforming training is performed as transmitter sector sweep (TXSS) training, which is transmitted and then generates sector sweep (SSW) feedback for reception by other wireless radio communication devices step; (e) (ii) receiving sector sweep frames from other wireless radio communication devices; (e) (iii) receiving sector sweep feedback information from other wireless radio communication devices; And (e) (iv) exchanging optimal transmit sector information with other wireless radio communication devices without incurring transmission contention.

2. The apparatus of any preceding embodiment, further comprising: executing the instructions to learn transmitter sector sweep (TXSS) training results from other wireless radio communication devices.

3. The apparatus of any preceding embodiment, wherein the wireless radio communication device comprises an access point (AP), or a station (STA).

4. An apparatus as in any preceding embodiment, wherein the transmitter sector sweep (TXSS) training is initiated by the computer processor when the station is a master station in a plurality of wireless radio communication devices.

5. An apparatus in any preceding embodiment, wherein the transmitter sector sweep (TXSS) training is initiated in response to receiving an initiator TXSS from a master station in a plurality of wireless radio communication devices.

6. The apparatus of any preceding embodiment, wherein initiating the sector level sweep (SLS) process comprises sending the polling signal followed by an initiator transmit sector sweep (TXSS) training to the computer processor as an initiator, or Initiated by another wireless radio communication device acting as an initiator.

7. An apparatus as in any preceding embodiment, wherein the polling signal is transmitted in a quasi-omnidirectional mode.

8. The apparatus of any preceding embodiment, further comprising executing instructions for controlling sleep and awake cycling of the wireless radio communication apparatus for a transmitter sector sweep (TXSS) power save mode.

9. The apparatus of any preceding embodiment, further comprising instructions for delaying generation of the sector sweep (SSW) feedback until all sector sweeping transmissions have been performed.

10. The apparatus of any preceding embodiment, further comprising executing instructions for gathering the best sector content for a plurality of stations when generating the sector sweep (SSW) feedback.

11. An apparatus in any preceding embodiment, wherein the instructions perform generation of sector sweep (SSW) feedback by using a MAC broadcast and a PHY quasi-forward mode.

12. An apparatus as in any preceding embodiment, wherein the SSW frames from each responder station carries feedback to the sector that is best for the link with the initiator or other stations to which the SSW frames are sent, (SSW) frames sent by the initiator, while the polling signal is transmitted to the best array sector according to information carried in the SSW frames of the other wireless radio communication devices. ≪ RTI ID = 0.0 > ≪ / RTI > further comprising executing instructions for the mode.

13. Apparatus in any preceding embodiment, wherein the transmitter and receiver operate at millimeter-wave (mmWave) radio frequencies.

14. An apparatus in any preceding embodiment, wherein the wireless radio communication device and other wireless radio communication devices form a wireless local area network (WLAN).

15. A wireless radio communication device that provides directional transmission between a plurality of wireless radio communication devices, comprising: (a) a transmitter configured to generate directional radio transmissions to other wireless radio communication devices in a range; (b) a receiver configured to receive radio transmissions from other wireless radio communication devices; (c) a computer processor coupled to the transmitter and the receiver to control communications between itself and other wireless radio communication devices; (d) a non-transitory computer-readable memory that stores instructions executable by a computer processor; (e) when executed by a computer processor, (SLS) process in which beamforming training is performed as transmitter sector sweep (TXSS) training, which is transmitted and then generates sector sweep (SSW) feedback for reception by other wireless radio communication devices step; (e) (ii) receiving sector sweep frames from other wireless radio communication devices; (e) (iii) receiving sector sweep feedback information from other wireless radio communication devices; And (e) (iv) exchanging optimal transmit sector information between the non-coordinator wireless radio communication devices, thereby allowing adjacent wireless radio communication devices to mutually learn the best sector information. Wireless radio communication device.

16. An apparatus in any preceding embodiment, wherein the wireless radio communication apparatus comprises an access point (AP), or a station (STA).

17. An apparatus in any preceding embodiment, wherein the transmitter sector sweep (TXSS) training is initiated by the computer processor when the station is a master station in a plurality of wireless radio communication devices.

18. An apparatus in any preceding embodiment, wherein the transmitter sector sweep (TXSS) training is initiated in response to receiving an initiator TXSS from a master station in a plurality of wireless radio communication devices.

19. The apparatus of any preceding embodiment, further comprising executing instructions for controlling sleep and awake cycling of the wireless radio communication device for a transmitter sector sweep (TXSS) power save mode.

20. The apparatus of any preceding embodiment, further comprising instructions for delaying generation of the sector sweep (SSW) feedback until all sector sweeping transmissions are performed.

Although the description herein includes many details, they should not be construed as limiting the scope of the disclosure, but merely as being provided as illustrations of some of the presently preferred embodiments. It is, therefore, to be understood that the scope of the disclosure fully encompasses other embodiments that may become apparent to those of ordinary skill in the art.

In the claims, reference to a singular element is not intended to mean "single" but "one or more" unless explicitly stated. All structural and functional equivalents to the elements of the disclosed embodiments known to those of ordinary skill in the art are expressly included herein by reference and are intended to be encompassed by the claims. Moreover, elements, components, or method steps in this disclosure are not intended to be offered to the public regardless of whether elements, components, or method steps are explicitly described in the claims. The claim elements of the specification are not to be construed as a " means and function " element unless the element is expressly recited using the phrase " means ". The claim elements of the specification are not to be construed as a " step and function " element unless the element is expressly recited using the phrase " step ".

Claims (20)

A wireless radio communication device that provides directional transmission between a plurality of wireless radio communication devices,
(a) a transmitter configured to generate directional radio transmissions to other wireless radio communication devices in the range;
(b) a receiver configured to receive radio transmissions from other wireless radio communication devices;
(c) a computer processor coupled to the transmitter and the receiver to control communications between itself and other wireless radio communication devices;
(d) a non-transitory computer-readable memory that stores instructions executable by the computer processor
Lt; / RTI >
(e) when executed by the computer processor,
(i) Transmitter sector sweep (TXSS) training, wherein a sector sweep (SSW) is transmitted and then generates sector sweep (SSW) feedback for reception by the other wireless radio communication devices Initiating a sector level sweep (SLS) process in which beam forming training is performed;
(ii) receiving sector sweep frames from the other wireless radio communication devices;
(iii) receiving sector sweep feedback information from the other wireless radio communication devices; And
(iv) exchanging optimal transmit sector information with the other wireless radio communication devices without incurring transmission contention
And performing the steps comprising: 2. The wireless radio communication device of claim 1, further comprising executing the instructions to learn transmitter sector sweep (TXSS) training results from the other wireless radio communication devices. 2. The wireless radio communication device of claim 1, wherein the wireless radio communication device comprises an access point (AP), or a station (STA). 2. The wireless radio communication device of claim 1, wherein the transmitter sector sweep (TXSS) training is initiated by the computer processor when the station is a master station within a plurality of wireless radio communication devices. 2. The wireless radio communication device of claim 1, wherein the transmitter sector sweep (TXSS) training is initiated in response to receiving an initiator TXSS from a master station in a plurality of wireless radio communication devices. 2. The method of claim 1, wherein initiating the sector level sweep (SLS) process comprises sending a polling signal followed by an initiator transmit sector sweep (TXSS) training to the computer processor as an initiator, A wireless radio communication device, initiated by another wireless radio communication device. 7. The wireless radio communication device of claim 6, wherein the polling signal is transmitted in a quasi-omnidirectional mode. 2. The wireless radio communication apparatus of claim 1, further comprising executing instructions for controlling sleep and awake cycling of the wireless radio communication apparatus for a transmitter sector sweep (TXSS) power save mode. 2. The wireless radio communication apparatus of claim 1, further comprising executing instructions to delay generation of the sector sweep (SSW) feedback until all sector sweeping transmissions are performed. 2. The wireless radio communication apparatus of claim 1, further comprising executing instructions for gathering the best sector contents for a plurality of stations when generating the sector sweep (SSW) feedback. The apparatus of claim 1, wherein the instructions perform generation of sector sweep (SSW) feedback by using MAC broadcast and PHY quasi-forward mode. 2. The method of claim 1, wherein SSW frames from each responder station carry feedback on the best sector for a link with initiators or other stations to which SSW frames are sent, Wherein the polling signal is included in sector sweep (SSW) frames sent by the initiator, while being transmitted to the best array sector according to the information carried in the SSW frames of the radio communication devices. Further comprising executing commands for the feedback mode. 2. The wireless radio communication apparatus of claim 1, wherein the transmitter and the receiver operate at millimeter-wave (mmWave) radio frequencies. 2. The wireless radio communication device of claim 1, wherein the wireless radio communication device and the other wireless radio communication devices form a wireless local area network (WLAN). A wireless radio communication device that provides directional transmission between a plurality of wireless radio communication devices,
(a) a transmitter configured to generate directional radio transmissions to other wireless radio communication devices in the range;
(b) a receiver configured to receive radio transmissions from other wireless radio communication devices;
(c) a computer processor coupled to the transmitter and the receiver to control communications between itself and other wireless radio communication devices;
(d) a non-transitory computer-readable memory that stores instructions executable by the computer processor
Lt; / RTI >
(e) when executed by the computer processor,
(i) beamforming training is performed as transmitter sector sweep (TXSS) training, where a sector sweep (SSW) is transmitted and then generates sector sweep (SSW) feedback for reception by the other wireless radio communication devices Initiating a sector level sweep (SLS) process;
(ii) receiving sector sweep frames from the other wireless radio communication devices;
(iii) receiving sector sweep feedback information from the other wireless radio communication devices; And
(iv) exchanging optimal transmit sector information between wireless radio communication devices that are not coordinators, thereby allowing adjacent wireless radio communication devices to mutually learn the best sector information
And performing the steps comprising: 16. The wireless radio communication device of claim 15, wherein the wireless radio communication device comprises an access point (AP), or a station (STA). 16. The wireless radio communication device of claim 15, wherein the transmitter sector sweep (TXSS) training is initiated by the computer processor when the station is a master station in a plurality of wireless radio communication devices. 16. The wireless radio communication device of claim 15, wherein the transmitter sector sweep (TXSS) training is initiated in response to receiving an initiator TXSS from a master station in a plurality of wireless radio communication devices. 16. The wireless radio communication device of claim 15, further comprising executing instructions for controlling sleep and awake cycling of the wireless radio communication device for a transmitter sector sweep (TXSS) power save mode. 16. The wireless radio communication apparatus of claim 15, further comprising executing instructions to delay generation of the sector sweep (SSW) feedback until all sector sweeping transmissions are performed.

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